On the OIL REDISCOVERY in Nigeria
There are two ways to steal oil. The first is to connect a pipe to a pipeline to convey the product to a barge. The barge can then supply artisanal refineries or go back and forth to a larger vessel anchored in an area where the river is deeper. This vessel will then head out to sea to refuel a tanker bound for South America, Europe or Asia. These tankers can also stay close to the West African coast and carry out transactions with other vessels on the high seas.
Source: tekedia.com